1. Field of the Invention
The present invention relates to a method and apparatus for quantitatively evaluating scintillation caused by surface unevenness. The present invention also relates to an antiglare film and a method of producing the same.
2. Description of Related Art
In display units such as LCDs, a phenomenon known as “scintillation” may occur. This is one of causes that make it difficult for the viewer to see the display. Scintillation is a phenomenon in which when the screen of a display unit is lit up, fine unevenness of luminance appears on the screen, and the position of the luminance unevenness appears to change as the viewing angle is changed. Scintillation is likely to appear particularly when white or green is displayed over the whole screen. Display units need to undergo an evaluation of the degree of such scintillation. The conventional practice is to use a 20-degree specular glossiness measuring method in which the intensity of light regularly reflected from a specimen when light is incident thereon at an angle of 20 degrees is measured. However, scintillation occurs due to surface unevenness or the like. Therefore, scintillation cannot accurately be evaluated by a method in which the intensity of reflected light is measured. Accordingly, a visual evaluation method has heretofore been employed to judge the quality of an antiglare film used to prevent scintillation.
However, it cannot be denied that the visual evaluation of scintillation is likely to cause differences between individuals in the evaluation and lacks accuracy. In development of antiglare films, etc., it has been demanded that the intensity of scintillation should be made capable of being evaluated quantitatively in order to understand the performance of antiglare films, etc.